Hierarchies of weakly monotone restarting automata

Hierarchies of weakly monotone restarting automata

It is known that the weakly monotone restarting automata accept exactly the growing contextsensitive langauges. We introduce a measure on the degree of weak monotonicity and show that the language classes obtained in this way form strict hierarchies for the various types of deterministic and nondeterministic restarting automata without auxiliary symbols.

Lookahead Hierarchies of Restarting Automata

The restarting automaton is a special kind of the linear bounded automaton with a read/write window of fixed length. It works in cycles, reducing the length of the actual word in each cycle. We study several versions of restarting automata and we show several hierarchies of language classes recognized by them with respect to the size of the read/write-window.

Cut Hierarchies for Restarting Automata and Marcus t-Contextual Grammars

t-contextual grammars with regular selection are considered for which all t insertions are performed in the same neighbourhood. The languages generated by these grammars are accepted by restarting automata with cut-index t. Here the classes of languages accepted by certain variants of restarting automata with limited cut-index are studied.

Restarting Tree Automata

CD-Systems of Restarting Automata